Disclosed is an embodiment of a plural-mode, plural information level, document encoding system and document. The document is printed with an integrated encoding of conventional bar coding information with its first level of bar code pattern information for optical reading by a conventional bar code reader, and integrally printed within the bar code pattern is a much finer and higher level information indicia pattern which does not interfere with the conventional bar code reading, yet is optically readable by a second, much higher resolution, optical reading system, to provide a much higher level of information from that second, much finer information indicia pattern. A high data density channel is thereby provided while maintaining the backward compatibility of the dual symbology to legacy bar code readers that are already in fielded systems.
It will be noted that many bar code readers can read multiple bar code symbologies, including readers that can read both one dimensional and two dimensional bar codes. There does not exist, however, a symbology which can be read by different kinds of readers at different data density levels.
Also in this manner, the user may be directed by the highly visible and well-recognized bar code pattern to provide scanning in the correct area or location of the document in which the other, much higher data density, indicia also exists, containing far more embedded information than can be provided by the bar code indicia itself, yet without any incompatibility or interference between these two optical data encoding and data reading systems.
The widespread prior art uses of digitally readable bar codes or their equivalents on almost any object or document is so ubiquitous as not to require discussion herein. They include common 1D and 2D bar codes, xe2x80x9ccheckerboardxe2x80x9d codes, the UPS or xe2x80x9cbulls eyexe2x80x9d codes, etc.. Thus, it will be appreciated as to the terms xe2x80x9cbar codesxe2x80x9d and the xe2x80x9cbarsxe2x80x9d of xe2x80x9cbar codesxe2x80x9d, as those terms are used in this particular application, that such xe2x80x9cbarsxe2x80x9d can be circular as well as linear in shape.
An important advantage of bar codes is that they are highly visible, distinctive, and universally known and recognizable. Thus, they provide a clear visual pointer to what area of a document or object bearing a bar code needs to be scanned.
However, for bar codes to be correctly read by any of various conventional bar code readers, which are typically simple low-resolution optical scanners with very limited image processing or enhancement, the bar coding pattern on the document requires a precisely defined pattern of multiple bars with clear, defined, xe2x80x9cwhite spacesxe2x80x9d in between the bars, with sharp, clear, boundary definitions and high contrast. Thus, the underprinting or overprinting of the bar code pattern areas of documents with other indicia is not normally allowed or considered appropriate.
Further by way of background, xe2x80x9cglyphxe2x80x9d encoding (also known under the proprietary names xe2x80x9cDataGlyphxe2x80x9d or xe2x80x9cSmart Paperxe2x80x9d) of various printed documents is also known in the art for various applications. xe2x80x9cGlyphsxe2x80x9d are an embedded digitally readable font, in particular a very fine pattern of machine readable indicia, preferably in very fine patterns of angled slash-mark appearing fonts like xe2x80x9c///  ////  // //xe2x80x9d, etc., (only very much smaller than as shown here) to be printed on various hardcopy documents. The proposed substitution of glyphs for bar codes has been suggested in some glyph literature. However, xe2x80x9cglyphsxe2x80x9d are by their very nature typically intended to be optically invisible to the naked eye, not recognizable, not within a clearly defined or bounded area of a document, and are not well known to the public.
Xerox Corp. U.S. Pat. No. 5,291,243 issued Mar. 1, 1994 (D/92224) to Dean A. Heckman, et al, discloses a system of integrated two color security patterns for checks or other security document printing, to prevent forgery. That patent specifically discusses providing buried glyph copies of any of the desired check data in the check background pattern image [e.g., Col. 12 line 58 to Col. 13 line 38], and specifically cites and incorporates by reference several of the below-cited patents. This and other references provide teachings for those skilled in the art of how to combine a fine, high-density, pattern of glyph encoded information into other patterns, backgrounds, text, or pictures, which glyph patterns are deliberately, effectively invisible to the naked eye, but machine-readable with surprising accuracy by known special glyph readers scanning the document or analyzing the electronic image thereof and readily separating the glyph pattern from its image background pattern.
Also particularly noted by way of background descriptions of Glyphs is Xerox Corp. European patent Application No. 92311676.8 published Jun. 30, 1993 as Publication No. 0 549 315 A1 by David L. Hecht, et al. (D/91764). The paragraph bridging Cols. 5-6 suggests the use of distinctly colored glyphs. Some additional examples of prior art on Glyphs in general includes an EPO Glyphs application Publication No. 459 792 published Dec. 4, 1991 (D/89190), which lists several glyph utilities and applications. Its parent U.S. application continuation issued in the U.S. on Jan. 23, 1996 as U.S. Pat. No. 5,486,686.
Other issued Xerox Corp. Glyph patents include U.S. Pat. No. 5,091,966, 5,128,525; 5,168,147; 4,716,438; 4,728,984; 4,757,348; 4,970,554, 5,060,980, 5,157,726, 5,221,833; 5,245,165; 5,278,400; 5,315,098; 5,317,646, 5,448,375, 5,449,895; 5,449,896, 5,453,605, 5,489,763, 5,521,372; 5,537,223; 5,572,010; 5,576,532; 5,611,575; 5,684,885; 5,706,099; 5,717,197; 5,761,686 and 5,771,245.
A further broadly glyph-related patent is Xerox Corp. U.S. Pat. No. 4,786,940 by J. Daniele. Also noted is J. Daniele U.S. Pat. No. 5,444,779 issued Aug. 22, 1995 (D/93027).
However, as noted, glyphs are effectively invisible to the naked human eye, and are not widely publicly understood, even if observed (unlike bar codes) and thus do not visually instruct a person wishing to scan a document as to where to scan the document in order to extract the imbedded (printed) information, i.e., which side and which area of the document to scan to extract the embedded glyph information. Likewise, there is normally no particular identified place on a document to print glyph information, much less a defined area of the document where the entire image background will normally (and very desirably for glyph information clarity and readability) be pure solid black and pure solid white areas.
It will be appreciated that the term xe2x80x9cdocumentxe2x80x9d as used herein in reference to the printing of bar codes and glyphs thereon is not limited to conventional sheets of paper or plastic. In this application it also broadly encompasses packaging, labels, and various other printable image substrates.
A specific feature of the specific embodiments disclosed herein is to provide an encoded document encoded with a plural mode, plural information level, integrated encoding system, wherein said document is printed with two separately readable but integrally printed first and second optically readable indicia patterns; said first indicia pattern comprising an otherwise conventional bar code pattern of spaced-apart optically readable bars encoded with a first set of encoded information readable by a conventional bar code reader, and said second optically readable indicia pattern comprising a second pattern encoded with a second set of encoded information which contains a higher level of information than said first set of encoded information, said second, pattern of optically readable indicia being integral said bar code pattern and not optically readable by a conventional bar code reader but optically readable by a fine pattern optical reader, said fine pattern of optically readable indicia integral said bar code pattern being several times smaller in dimension than said spacing between said optically readable bars of said bar code pattern or the width of said bars.
Further specific features disclosed in the embodiment herein, individually or in combination, include those wherein said indicia of said second pattern of optically readable indicia integral said bar code pattern is at least 20 times smaller in area than the area of said spacing between said optically readable bars of said bar code pattern; and/or wherein said second optically readable indicia pattern is printed in thin glyphs integrally printed within said bar code pattern and/or wherein said second optically readable indicia pattern is a pattern of fine optically readable indicia which is within said optically readable bars of said bar code pattern; and/or wherein said second optically readable indicia pattern comprises a multiple fine spaced optically readable indicia pattern printed in between said spaced-apart optically readable bars of said bar pattern; and/or wherein at least one of said optically readable bars of said bar code pattern is formed by a dense pattern of said second optically readable indicia; and/or wherein said second optically readable indicia pattern is a different color than said bar code pattern.
Another disclosed feature of the embodiment is a dual encryption method for providing and obtaining a substantially increased amount of optically readable information from an otherwise conventional and highly visible bar code pattern on a document without interfering with the conventional optical reading of the conventional information in said bar code, comprising integrally embedding a second and finer pattern of encoded optically machine readable indicia within said bar code pattern, containing a higher level of information, to provide two different levels of information within a conventional bar code pattern, and scanning said bar code pattern with a conventional bar code reader to extract conventional bar coded information embedded in said bar code pattern, and also scanning said same bar code pattern with a different, higher resolution, optical scanner to extract said second optically readable indicia pattern therefrom; and/or wherein said second and much finer optical indicia pattern is a thin glyph code pattern; and/or wherein said second pattern comprises optical indicia at least 20 times smaller than said bar code pattern.
As to specific components of the subject apparatus, or alternatives therefor, it will be appreciated that, as is normally the case, some such components are known per se in other apparatus or applications which may be additionally or alternatively used herein, including those from art cited herein. All references cited in this specification, and their references, are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features, and/or technical background. What is well known to those skilled in the art need not be described here.